Abstract: In a method and x-ray system for controlling the electron current in an x-ray tube emitted from a continuously heated electron emitter with an allocated focussing electrode to an anode, the potential of the focussing electrode is pulsed between a conducting-state voltage, selected dependent on the desired size of the focal spot and/or the tube voltage of the electron beam on the anode, and a blocking voltage interrupting the electron current to the anode, the pulsewidth being modulated to control the electron current.

Abstract: A direct-heated flat emitter for generating a homogenous electron beam, particularly for x-ray tubes, has two terminal lugs for the heating current supply formed at the edge of the perimeter of the emission surface and the emission surface is subdivided into interconnects by slits. The slits have a width no less than 10 .mu.m and no greater than 1% of the length of a diagonal of the smallest rectangle which can circumscribe the emission surface.

Abstract: In an X-ray device which includes an X-ray tube (12) provided with means (15, 22, 23) for influencing the electron flow through the X-ray tube (12), a control voltage for the means for influencing the electron flow is customarily generated by means of a complex circuit which, because of its size, is not suitable to be accommodated within the protective tube housing. This has the drawback that the control voltage for the X-ray tube, usually of high voltage potential, must be supplied additionally to the high-voltage supply. Therefore, it is desirable to realize a simple generation means the control voltage which is suitable for accommodation in the protective tube housing. To this end, the invention proposes a piezoelectric transformer (21, 24, 25) for generating the control voltage for the X-ray tube. The invention also relates to a piezoelectric transformer which is particularly suitable for generating such a control voltage.

Abstract: An X-ray tube with a cathode and an anode arranged in a vacuum housing has an electromagnet for deflecting the electron beam emanating from the cathode and proceeding to the anode, the electromagnet having a yoke with two legs connected to one another by a base section, with a winding surrounding the base section. The base section with the winding is located outside the vacuum housing. The legs of the yoke of the electromagnet extend into the vacuum housing so that the electron beam proceeds between the two legs.

Abstract: An x-ray generator has a beam guidance system including an air coil and a toroidal solenoid coil, a ring anode surrounding the patient to be examined and arranged axially offset relative to the beam guidance, and individually driveable electron-optical components couple the electrons, which orbit on a circular specified path in the magnetic dipole field of the air coil, out of that path, deflect them in the axial direction, and focus them onto a segment of the ring anode allocated to the respectively activated out-coupling element.

Abstract: In an X-ray diagnostic apparatus, for acquiring the cross-section, position and/or alignment, relative to a target, of an electron beam generated by an electron generating system, at least one conductor is provided in the region of the target so that a signal can be derived by the conductor under the influence of the electron beam and supplied to an evaluation stage. The conductor is composed of a material having an atomic number lower than that of tungsten, so that no undesirable radiation arises due to the interaction of the electrons with this conductor.

Abstract: A cathode system for an x-ray tube has an electron emitter and a further electrode arranged between electron emitter and the x-ray tube anode. This further electrode can be connected to a potential deviating from the potential of the electron emitter with a switching stage having a pulse-pause (on-off) ratio set to produce the desired tube current.

Abstract: A scanned volume computerized tomography scanner in which an electron beam is scanned along a target to generate successive cones of x-rays. A vane collimator receives said x-rays and from successive adjacent fan becomes for irradiating a volume of an object. A detector array receives the x-ray fan becomes and generates signals representative of the transmitted x-ray amplitude across the fan beams. The object and x-ray source are rotated relative to one another to collect data for reconstructing an image of the scanned volume.

Abstract: An X-ray tube has a vacuum housing that contains a cathode and an anode, the housing having a radiation exit window. The radiation exit window is electrically conductive, and lies at cathode potential, and is electrically insulated against the vacuum housing, which lies at a potential that is positive in relation to the cathode potential.

Abstract: The x-ray source of the present invention comprises a charged particle beam generator and a vacuum enclosure assembly. The charged particle beam generator includes only a single electrical connection for providing high voltage to the electron gun. The power for the active circuits in the high voltage terminal of the charged particle beam generator is provided by a unique isolation transformer that has minimal losses and generates controlled magnetic flux. The generated charged particle beam is controlled through a series of dynamic and static focus coils and moved across the inner face of the target by a stepping coil assembly comprising x and y deflection coils as well as an x step and preferably a y step coil. Further, to minimize power usage, a control grid pinches off the charged particle beam during the stepping of the beam.

Abstract: The note path of a banknote validator has a U-shaped transverse cross section. A transverse strip of the note path is illuminated by light from a light transmitting station by means of a unitary light guide which has an arcuate portion conforming to the transverse cross section of the note path. Light reflected from a banknote within the note path, is captured by the light guide and guided to a light receiving station. The light guide is shaded such that a transverse strip of the note path is substantially evenly illuminated. The U-shape of the note path also assists the insertion of notes into the validator, as an inserted note is used to bow during insertion thereby increasing its rigidity.

Abstract: In an X-ray computerized tomography apparatus, a water phantom is interposed between an X-ray tube unit and an X-ray detector in place of a subject under examination and a plurality of pieces of data detected by a plurality of X-ray detector elements are previously measured as a pieces of compensation data while shifting the X-focal point to different positions. Compensation data corresponding to the actual position of the X-ray focal point, which shifts according to the thermal state of the X-ray tube unit, is selected to correct detect data obtained for a subject under examination, permitting optimum compensation of variations in sensitivity among the X-ray detector elements for any position of the X-ray focal point, thereby preventing a ring-like artifact from being produced on a tomography image.

Abstract: Precise alignment of the focal spot position on an x-ray CT system is achieved using a deflection coil that produces a magnetic field which acts on the electron beam path in the x-ray tube. A variable current power supply drives the deflection coil and is controlled by input signals to align the focal spot at a static reference position, to correct for focal spot drift between scans, and to wobble the focal spot position during a scan or between scans.

Abstract: A self-biased focus X-ray generating tube has a cathode assembly connected by its insert end to a multiplier from outside a vacuum envelope. The multiplier rectifies and multiplies AC power of the filament drive to provide a DC voltage, which is applied to the cathode assembly for pinching the electron beam traveling between the cathode and the anode target of X-ray tube and, as a result, improving the quality of the focal spot.

Abstract: A portable x-ray tube 68 for producing x-rays, the tube 68 having an energy source 74 which directs energetic particles or photons at an electron multiplier 80 coupled to the energy source 74. A voltage source 84 applies a multiplier voltage across the electron multiplier 80. When triggered by the energy source 74, the electron multiplier 80 creates a multitude of electrons 28 directed towards a target anode 90 that receives the electrons and produces x-rays 30. The target anode 90 is coupled at a voltage difference of at least 3 kV relative to the electron multiplier 80 so as to define an electron acceleration region 32 between the electron multiplier 80 and the target anode 90. The target anode 90 contains an element having an atomic number greater than 11. A low pressure enclosure 70 contains the electron multiplier 80 and the target anode 90. The low pressure enclosure 70 includes a window 92 for allowing the x-rays 30 to pass through substantially unchanged.

Abstract: X-ray images are produced on a monitor display screen by situating the subject between a detector having a minute x-ray sensitive area and an x-ray source having an extensive anode plate on which an x-ray origin point is swept in a raster pattern similar to the raster of the display monitor. Operating parameters of the x-ray source are controlled by digital data processing circuits which enable magnification of operator selected areas of the image by reducing the size of x-ray source raster pattern and repositioning of the raster pattern on the anode plate in response to operator actuation of one or more computer input devices. In the preferred form, the system also enables image enhancements and control of image characteristics such as contrast and brightness in response to actuations of the input devices or in response to programming. X-ray exposure and image acquisition time may be reduced by operator selection of only specific areas of particular interest for high resolution scanning.

Abstract: An X-ray computerized tomographic (CT) apparatus capable of facilitating alignment of focal spot position at the time of replacing an X-ray tube anew and capable of easily correcting the focal spot position even when the focal spot position of the X-ray tube is deviated. Thereby, the focal spot position of the X-ray tube remains fixed in a predetermined position. The X-ray computerized tomographic (CT) apparatus includes an X-ray tube which is freely movable in at least one of a horizontal direction and a vertical direction; a detection unit for detecting a dislocated degree of the focal spot position of the X-ray tube; and a controlling unit for automatically controlling the focal spot position of the X-ray tube based on data obtained from the detection unit so that the focal spot position of the X-ray tube remains fixed in a predetermined position.

Abstract: A beam position detecting device wherein the intensity of a radiation beam from a synchrotron ring is measured on the basis of electric currents flowing through two wires, while accumulated electric current in the synchrotron ring is measured by using a current transformer. The beam position can be determined accurately on the basis of these measured values.

Abstract: A mammography X-ray tube providing increased X-ray intensity for shortening patient exposure times to eliminate motion artifacts. The cathode design permits superpositioning of electron beam from multiple filaments.

Abstract: In order to construct a radiotherapy apparatus which can irradiate a point in the body of a patient in an optional direction with high accuracy, an accelerated electron beam is controlled electrically by using deflectors so as to irradiate a plurality of radioactive ray generating positions, a collimator is provided so that a radioactive ray generated from the positions can irradiate one point of a portion of the patient's body to be treated, and a gantry can be rotated mechanically.

Abstract: X-ray images are produced on a monitor display screen by situating the subject between a detector having a minute x-ray sensitive area and an x-ray source having an extensive anode plate on which an x-ray origin point is swept in a raster pattern similar to the raster of the display monitor. Operating parameters of the x-ray source are controlled by digital data processing circuits which enable magnification of operator selected areas of the image by reducing the size of x-ray source raster pattern and repositioning of the raster pattern on the anode plate in response to operator actuation of one or more computer input devices. In the preferred form, the system also enables image enhancements and control of image characteristics such as contrast and brightness in response to actuations of the input devices or in response to programming. X-ray exposure and image acquisition time may be reduced by operator selection of only specific areas of particular interest for high resolution scanning.

Abstract: A scanning electron beam computed tomography scanner is disclosed herein and includes means defining a vacuum chamber, means for producing an electron beam at one location in the chamber and for directing it to a second location therein, a target located at a third position therein of the type which produces X-rays as a result of the impingement thereon by the electron beam, means for focusing the beam onto the target in the form of a beam spot and for scanning the beam spot across the target along a particular scan path in order to produce X-rays, and means for monitoring the profile, position, and orientation of the beam spot at a plurality of locations along the scan path. The specific scanner disclosed also includes an arrangement for determining from the signals produced by the monitoring devices if the beam spot conforms to as desired profile, position, and orientation and automatically adjusting the electron beam such that its profile, position, and orientation conform to desired values.

Abstract: Disclosed is a device that can be used to obtain voltages for the biasing of the electrodes used to deflect the electron beam emitted by a cathode of an X-ray tube. Four DC voltages .+-.V.sub.1 and .+-.V.sub.2 are generated and applied to a mixing circuit in which they are added by using diodes to floating reference pulse voltages .+-.V.sub.3 so as to obtain voltages VS.sub.1, VS.sub.2, VS'.sub.1, VS'.sub.2 for the charging of capacitors such that:VS.sub.1 =V.sub.3 -V.sub.1 and VS.sub.2 =-V.sub.3 +V.sub.2VS'.sub.1 =-VS.sub.3 +V.sub.2 and VS'.sub.2 =V.sub.3 -V.sub.

Abstract: A voltage control (22) controls the voltage applied between an anode (12) and a cathode filament (14) of an x-ray tube (10). A filament control (16) controls the amount of current fed through the filament. A voltage controlled oscillator (40) and counter (42) monitor the magnitude, if any, of a tube current (24) flowing between the cathode and the anode to generate x-rays (26). A microprocessor (50) calibrates the filament current such that the filament current value stored in a filament current look-up table (122) for each selectable tube voltage and tube current combination actually produces the selected tube current. The filament current is initialized (60) to a small current value and progressively incremented (66) until a commencement of the tube current (24) is monitored (64).

Abstract: A modular electrical assembly is enclosed in an elastomeric weathershed housing, and has a plurality of electrical components aligned in a row and in electrical connection with one another via their axially-directed ends and under an axially-directed compressive force via a non-conductive filament winding. The filament winding defines a crisscross pattern with lateral openings for venting gas upon failure of one of the electrical components. The openings can be filled with fracturable epoxy or other insulating materials such as silicone grease.

Abstract: An apparatus for slit radiography is provided with a slot diaphragm to form a fan-shaped X-ray beam with which a body can be scanned. Controllable attenuating elements interact with the slit diaphragm to influence sectors of the fan-shaped X-ray beam. They are controlled by signals representing the instantaneous transmission of the body in the corresponding sectors. The hardness of the fan-shaped X-ray beam is varied periodically in a predetermined manner. Synchronously with the periodic variation of the hardness of the X-ray beam the attenuating elements are oscillated. The oscillation of the attenuating elements is superimposed at each instant on the instantaneous position determined by the signals representing the instantaneous body transmission. The amplitude of the oscillation is less than the height of the slit of the slit diaphragm. The influence on the X-ray beam is most at the instants at which the hardness is greatest.

Abstract: Radiation of specific material within a subject is accomplished by use of a beam of x-radiation modulated at a microwave frequency. The beam with its modulation is directed at the subject wherein the material interacts with the beam to extract a portion of the radiant energy carried by the beam. In the interaction, an electric field at the modulating frequency appears at the material. By selecting the modulated frequency equal to a resonant interactive microwave frequency of the material, a photon at the microwave frequency is absorbed by the material to alter its physical and chemical properties. By way of example, the material may be an oncogene or virus having a macromolecule and constituting a malignancy within a living subject. Absorption of the modulated radiation selectively destroys the malignancy. The klystron is disposed along the path of an electron beam in an x-ray source for modulating the electron beam and the resulting x-ray beam.

Abstract: A microfocus type X-ray system in which the electron beam current is generally operated in a milliampere range at a constant power, and the beam is subjected to electronic focusing for selected beam width and steering for directional control.

Abstract: A head-activated fluoroscopic control which is characterized in a preferred embodiment by a continuous wave infrared transmitter located in a cartridge adapted for attachment to eyeglasses, a headband or other headpiece worn by a surgeon or attending physician and a detector or receiver tuned to the frequency of the continuous wave infrared transmitter for receiving a partially collimated infrared signal beam and activating a fluoroscope. The infrared transmitter emits the collimated beam and the beam is received by the receiver when the surgeon's head is turned toward the fluoroscope monitor upon which the receiver rests or in which the receiver is mounted, to facilitate selective operation of the fluoroscope during surgery.

Abstract: Roentgen lithography aparatus comprises a roentgen tube for producing long wave roentgen radiation for forming an image of a mask on a substrate. The roentgen tube comprises an electron gun having a glow cathode and a grid, electron beam deflecting and focussing coils, a target on which the electron beam is projected and an exit window through which roentgen rays from the target are projected through a lithography mask onto a substrate. The glow cathode and the target are of high atomic number high melting point material, such as tunsten. The grip has an annular flange with a central opening in which the tip of the glow cathode is disposed. The front face of the flange facing the target is frustoconical with an included angle of about 100.degree. to 140.degree. while the rear face is plane. The angle between the front and rear faces as measured in a radial plane is about 15.degree. to 60.degree.. The focussing coil focusses the electron beam into a focal spot on the target having a diameter less than 10.sup.

Abstract: An x-ray tube contains a plurality of filaments each with an associated focus cup control to allow it to change rapidly between discrete emission intensities. The cathode structure of the x-ray tube is constructed so that each filament is located in a separate focus cup structure. However, the focus cup structures are electrically isolated so that a separate bias potential can be applied to each focus cup structure. By separately biasing each focus cup structure, the emission from each of the filaments can be controlled independently.

Abstract: An X-ray tube has a cathode assembly for emitting an electron beam and an anode target facing this assembly in an evacuated envelope. The anode target defines a target surface that is slightly inclined to the electron beam axis and the direction in which it is inclined coincides with an X-ray irradiation direction. The cathode assembly comprises a flat cathode with a flat electron emission surface and a focussing electrode which focuses electrons emitted by the cathode. The cathode's electron emission surface is elongated and its long axis is coincident with the direction of X-ray irradiation. The focussing electrode possesses an axially symmetric opening with generally the same dimensions lengthways and crosswise.

Abstract: A structure and method for providing optimum recording of X-ray images without need for experimenting to learn optimum X-ray tube voltage, current, anode focal spot size and exposure time. The method and structure of this invention sample the radiation passed through an object to be radiographed during a short portion of the total exposure time and adjust voltage, current and focal spot size so that the radiation delivered by the X-ray tube during the remainder of the exposure time will produce optimum contrast between structures within the object being radiographed, also optimum sharpness of the image and optimum darkening of a film, xerographic picture, fluoroscopic image, or other recording medium. The method and structure of this invention account for variations in absorption coefficient between one object to be radiographed and the next. This invention is particularly useful for medical applications, and in the medical field, particularly important in mammography.

Abstract: In an exemplary embodiment a fine electron beam is generated which impinges on an elemental part of an anode focus region. A beam deflection system is controlled by a control circuit such that the point of impingement of the electron beam on the anode focus region moves along a predetermined path whose configuration effectively determines the desired focus size and shape.

Abstract: A line locking system for use with X-ray video imaging equipment comprising: a system oscillator, a divider for frequency dividing the output of the system oscillator to obtain a signal having a frequency that is an integer multiple of the line frequency, a comparator for comparing the phase of the integer multiple signal to the phase of the line signal and means for controlling the oscillator frequency responsive to the output of the comparator.

Abstract: Anode life in an x-ray tube is extended by applying a reduced power density to the anode to afford controlled heating of the anode to a predetermined ductile temperature prior to operating the tube at full power. Controlled heating of the anode is accomplished by defocusing the electron beam for a period of time sufficient to enable the anode to reach the desired temperature. The electron beam source of the tube may also be controlled during heating of the anode so as to supply a reduced beam current.

Abstract: A scanning beam computed tomography scanner is disclosed herein and includes means defining a vacuum chamber, means for producing an electron beam at one location in the chamber and for directing it to a second location therein, a target of the type which produces X-rays as a result of the impingement thereon by the electron beam, and means for focusing the beam onto the target in the form of a beam spot and for scanning the beam spot across the target along a particular scan path in order to produce X-rays. The specific scanner disclosed also includes an arrangement for monitoring the profile, position and orientation of the beam spot at a plurality of different points along the scan path.

Abstract: An X-ray control device is held in a constant position relative to an X-ray tube and an X-ray detector, while the X-ray tube is moved toward or away from the rotational scanning axis at which an object to be examined is located. The X-ray control device allows selection of a spot size and a tube voltage of the X-ray tube. The X-ray control device is controlled in synchronism with a shift mechanism. When the X-ray tube is close to the object, a smaller spot and a higher tube voltage than those when the X-ray tube is separated from the object are selected.

Abstract: A method of extending the lifetime of an electron beam filament, typically LaB.sub.6 by applying power to the filament over a preselected period in a substantially linear manner. The time period is typically 20 minutes before a steady state power level is attained with a fully stabilized instrument. Power-down is a reverse of the power-up sequence until all power is removed.

Abstract: The invention relates to the polarization of a cathode of an X-ray tube by a high voltage cable comprising less conductors than the tube has polarization terminals. The missing voltages are processed by a device according to the invention, which comprises a voltage divider positioned between two of the voltages applied to the input terminals. It permits the use of standard long high voltage cables with limited stray capacitance without inducing dimensional control losses with respect to the tube foci.Application to multifocus X-ray sources.

Abstract: In an auxiliary-voltage DC source for supplying an electric circuit and, more particularly, one at a high potential in an electron gun without an isolation transformer, the primary winding of a current transformer is located in an alternating-current section of the electric circuit. The current transformer has at least one secondary winding which is connected through a rectifier to a parallel regulator for providing the auxiliary-voltage.

Abstract: A microfocus type X-ray system in which the electron beam power is generally operated in a milliampere range at a constant power, and the beam is subjected to electromagnetic focusing for selected beam width.

Abstract: A power supply is switchable to apply a low kilovoltage and a relatively higher kilovoltage alternately to the anode of an X-ray tube that includes a filament and a control grid. A grid bias voltage generator uses an inverter driven in the kilohertz frequency range to feed the primary winding of a first transformer whose parasitic capacitance and inductance are used to produce a peak ac output voltage from the secondary of the first transformer at resonant frequency. The secondary output voltage is rectified and the resulting negative bias voltage is applied to the control grid synchronously with the high kilovoltage being applied to the anode so the X-ray tube current is then relatively low. A less negative or zero bias voltage is applied to the grid synchronously with the lower kilovoltage being applied to the anode so the X-ray tube current is then relatively high and substantially limited by the temperature and emissivity of the filament.

Abstract: In X-ray tubes comprising a metal grid, it may occur that the necessary emission current cannot be reached in unfavorable circumstances. This situation is improved by the invention in that the high voltage for the X-ray tube is derived from at least three series connected high voltage generators, the first and the second generator being connected to the anode and the cathode, respectively, of the X-ray tube while the third generator can be connected either to the anode side (in the case of high tube voltages) or to the cathode side (in the case of low tube voltage) by means of a switching device.

Abstract: An exemplary embodiment includes a television installation for the transmission of the X-ray image, a dose rate device for supplying a dose rate value during fluoroscopy, and a control circuit for controlling the size of the focus of the X-ray tube, to which at least one dose rate value of the dose rate device is supplied. An X-ray tube is present with at least one control electrode for the determination of the focus size via the electrode potential. The control electrode is connected with the control circuit via a control voltage generator. In the control circuit, data is stored which establishes the focus size at the smallest possible value, in dependence upon the dose rate value, the permissible load of the X-ray tube, and upon radiography values.

Abstract: A structure and method for providing optimum recording of X-ray images without need for experimenting to learn optimum X-ray tube voltage, current, anode focal spot size and exposure time. The method and structure of this invention sample the radiation passed through an object to be radiographed during a short portion of the total exposure time and adjust voltage, current and focal spot size so that the radiation delivered by the X-ray tube during the remainder of the exposure time will produce optimum contrast between structures within the object being radiographed, also optimum sharpness of the image and optimum darkening of a film, xerographic picture, fluoroscopic image, or other recording medium. The method and structure of this invention account for variations in absorption coefficient between one object to be radiographed and the next. This invention is particularly useful for medical applications, and in the medical field, particularly important in mammography.